# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1282398696 -3600
# Node ID 0f5a8d530fcd4912ff43378480d9e463bf5c33a5
# Parent  1dccff7df2d53e57065c1fe2a3dda8603c8df58b
verse.plugins.disco: Add disco plugin originally developed by Hubert Chathi for Riddim, but here adapted for Verse with new APIs added to allow disco'ing the local server and remote entities

diff -r 1dccff7df2d5 -r 0f5a8d530fcd plugins/disco.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/disco.lua	Sat Aug 21 14:51:36 2010 +0100
@@ -0,0 +1,349 @@
+-- Verse XMPP Library
+-- Copyright (C) 2010 Hubert Chathi <hubert@uhoreg.ca>
+-- Copyright (C) 2010 Matthew Wild <mwild1@gmail.com>
+-- 
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+local st = require "util.stanza"
+local b64 = require("mime").b64
+-- NOTE: The b64 routine in LuaSocket 2.0.2 and below
+-- contains a bug regarding handling \0, it's advisable
+-- that you use another base64 routine, or a patched
+-- version of LuaSocket.
+-- You can borrow Prosody's (binary) util.encodings lib:
+--local b64 = require("util.encodings").base64.encode
+
+local sha1 = require("util.sha1").sha1
+
+local xmlns_disco = "http://jabber.org/protocol/disco";
+local xmlns_disco_info = xmlns_disco.."#info";
+local xmlns_disco_items = xmlns_disco.."#items";
+
+function verse.plugins.disco(stream)
+	stream.disco = { cache = {}, info = {} }
+	stream.disco.info.identities = {
+		{category = 'client', type='pc', name='Verse'},
+	}
+	stream.disco.info.features = {
+		{var = 'http://jabber.org/protocol/caps'},
+		{var = 'http://jabber.org/protocol/disco#info'},
+		{var = 'http://jabber.org/protocol/disco#items'},
+	}
+	stream.disco.items = {}
+	stream.disco.nodes = {}
+
+	stream.caps = {}
+	stream.caps.node = 'http://code.matthewwild.co.uk/verse/'
+
+	local function cmp_identity(item1, item2)
+		if item1.category < item2.category then
+			return true;
+		elseif item2.category < item1.category then
+			return false;
+		end
+		if item1.type < item2.type then
+			return true;
+		elseif item2.type < item1.type then
+			return false;
+		end
+		if (not item1['xml:lang'] and item2['xml:lang']) or
+			 (item2['xml:lang'] and item1['xml:lang'] < item2['xml:lang']) then
+			return true
+		end
+		return false
+	end
+
+	local function cmp_feature(item1, item2)
+		return item1.var < item2.var
+	end
+
+	local function calculate_hash()
+		table.sort(stream.disco.info.identities, cmp_identity)
+		table.sort(stream.disco.info.features, cmp_feature)
+		local S = ''
+		for key,identity in pairs(stream.disco.info.identities) do
+			S = S .. string.format(
+				'%s/%s/%s/%s', identity.category, identity.type,
+				identity['xml:lang'] or '', identity.name or ''
+			) .. '<'
+		end
+		for key,feature in pairs(stream.disco.info.features) do
+			S = S .. feature.var .. '<'
+		end
+		-- FIXME: make sure S is utf8-encoded
+		--stream:debug("Computed hash string: "..S);
+		--stream:debug("Computed hash string (sha1): "..sha1(S, true));
+		--stream:debug("Computed hash string (sha1+b64): "..b64(sha1(S)));
+		return (b64(sha1(S)))
+	end
+
+	setmetatable(stream.caps, {
+		__call = function (...) -- vararg: allow calling as function or member
+			-- retrieve the c stanza to insert into the
+			-- presence stanza
+			local hash = calculate_hash()
+			return st.stanza('c', {
+				xmlns = 'http://jabber.org/protocol/caps',
+				hash = 'sha-1',
+				node = stream.caps.node,
+				ver = hash
+			})
+		end
+	})
+	
+	function stream:add_disco_feature(feature)
+		table.insert(self.disco.info.features, {var=feature});		
+	end
+
+	function stream:jid_has_identity(jid, category, type)
+		local cached_disco = self.disco.cache[jid];
+		if not cached_disco then
+			return nil, "no-cache";
+		end
+		local identities = self.disco.cache[jid].identities;
+		if type then
+			return identities[category.."/"..type] or false;
+		end
+		-- Check whether we have any identities with this category instead
+		for identity in pairs(identities) do
+			if identity:match("^(.*)/") == category then
+				return true;
+			end
+		end
+	end
+
+	function stream:jid_supports(jid, feature)
+		local cached_disco = self.disco.cache[jid];
+		if not cached_disco or not cached_disco.features then
+			return nil, "no-cache";
+		end
+		return cached_disco.features[feature] or false;
+	end
+	
+	function stream:get_local_services(category, type)
+		local host_disco = self.disco.cache[self.host];
+		if not(host_disco) or not(host_disco.items) then
+			return nil, "no-cache";
+		end
+		
+		local results = {};
+		for _, service in ipairs(host_disco.items) do
+			if self:jid_has_identity(service.jid, category, type) then
+				table.insert(results, service.jid);
+			end
+		end
+		return results;
+	end
+	
+	function stream:disco_local_services(callback)
+		self:disco_items(self.host, nil, function (items)
+			local n_items = 0;
+			local function item_callback()
+				n_items = n_items - 1;
+				if n_items == 0 then
+					return callback(items);
+				end
+			end
+			
+			for _, item in ipairs(items) do
+				if item.jid then
+					n_items = n_items + 1;
+					self:disco_info(item.jid, nil, item_callback);
+				end
+			end
+			if n_items == 0 then
+				return callback(items);
+			end
+		end);
+	end
+	
+	function stream:disco_info(jid, node, callback)
+		local disco_request = verse.iq({ to = jid, type = "get" })
+			:tag("query", { xmlns = xmlns_disco_info, node = node });
+		self:send_iq(disco_request, function (result)
+			if result.attr.type == "error" then
+				return callback(nil, result:get_error());
+			end
+			
+			local identities, features = {}, {};
+			
+			for tag in result:get_child("query", xmlns_disco_info):childtags() do
+				if tag.name == "identity" then
+					identities[tag.attr.category.."/"..tag.attr.type] = tag.attr.name or true;
+				elseif tag.name == "feature" then
+					features[tag.attr.var] = true;
+				end
+			end
+			
+
+			if not self.disco.cache[jid] then
+				self.disco.cache[jid] = { nodes = {} };
+			end
+
+			if node then
+				if not self.disco.cache.nodes[node] then
+					self.disco.cache.nodes[node] = { nodes = {} };
+				end
+				self.disco.cache[jid].nodes[node].identities = identities;
+				self.disco.cache[jid].nodes[node].features = features;
+			else
+				self.disco.cache[jid].identities = identities;
+				self.disco.cache[jid].features = features;
+			end
+			return callback(self.disco.cache[jid]);
+		end);
+	end
+	
+	function stream:disco_items(jid, node, callback)
+		local disco_request = verse.iq({ to = jid, type = "get" })
+			:tag("query", { xmlns = xmlns_disco_items, node = node });
+		self:send_iq(disco_request, function (result)
+			if result.attr.type == "error" then
+				return callback(nil, result:get_error());
+			end
+			local disco_items = { };
+			for tag in result:get_child("query", xmlns_disco_items):childtags() do
+				if tag.name == "item" then
+					table.insert(disco_items, {
+						name = tag.attr.name;
+						jid = tag.attr.jid;
+					});
+				end
+			end
+			
+			if not self.disco.cache[jid] then
+				self.disco.cache[jid] = { nodes = {} };
+			end
+			
+			if node then
+				if not self.disco.cache.nodes[node] then
+					self.disco.cache.nodes[node] = { nodes = {} };
+				end
+				self.disco.cache.nodes[node].items = disco_items;
+			else
+				self.disco.cache[jid].items = disco_items;
+			end
+			return callback(disco_items);
+		end);
+	end
+	
+	stream:hook("iq/http://jabber.org/protocol/disco#info", function (stanza)
+		if stanza.attr.type == 'get' then
+			local query = stanza:child_with_name('query')
+			if not query then return; end
+			-- figure out what identities/features to send
+			local identities
+			local features
+			if query.attr.node then
+				local hash = calculate_hash()
+				local node = stream.disco.nodes[query.attr.node]
+				if node and node.info then
+					identities = node.info.identities or {}
+					features = node.info.identities or {}
+				elseif query.attr.node == stream.caps.node..'#'..hash then
+					-- matches caps hash, so use the main info
+					identities = stream.disco.info.identities
+					features = stream.disco.info.features
+				else
+					-- unknown node: give an error
+					local response = st.stanza('iq',{
+						to = stanza.attr.from,
+						from = stanza.attr.to,
+						id = stanza.attr.id,
+						type = 'error'
+					})
+					response:tag('query',{xmlns = 'http://jabber.org/protocol/disco#info'}):reset()
+					response:tag('error',{type = 'cancel'}):tag(
+						'item-not-found',{xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas'}
+					)
+					stream:send(response)
+					return true
+				end
+			else
+				identities = stream.disco.info.identities
+				features = stream.disco.info.features
+			end
+			-- construct the response
+			local result = st.stanza('query',{
+				xmlns = 'http://jabber.org/protocol/disco#info',
+				node = query.attr.node
+			})
+			for key,identity in pairs(identities) do
+				result:tag('identity', identity):reset()
+			end
+			for key,feature in pairs(features) do
+				result:tag('feature', feature):reset()
+			end
+			stream:send(st.stanza('iq',{
+				to = stanza.attr.from,
+				from = stanza.attr.to,
+				id = stanza.attr.id,
+				type = 'result'
+			}):add_child(result))
+			return true
+		end
+	end);
+
+	stream:hook("iq/http://jabber.org/protocol/disco#items", function (stanza)
+		if stanza.attr.type == 'get' then
+			local query = stanza:child_with_name('query')
+			if not query then return; end
+			-- figure out what items to send
+			local items
+			if query.attr.node then
+				local node = stream.disco.nodes[query.attr.node]
+				if node then
+					items = node.items or {}
+				else
+					-- unknown node: give an error
+					local response = st.stanza('iq',{
+						to = stanza.attr.from,
+						from = stanza.attr.to,
+						id = stanza.attr.id,
+						type = 'error'
+					})
+					response:tag('query',{xmlns = 'http://jabber.org/protocol/disco#items'}):reset()
+					response:tag('error',{type = 'cancel'}):tag(
+						'item-not-found',{xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas'}
+					)
+					stream:send(response)
+					return true
+				end
+			else
+				items = stream.disco.items
+			end
+			-- construct the response
+			local result = st.stanza('query',{
+				xmlns = 'http://jabber.org/protocol/disco#items',
+				node = query.attr.node
+			})
+			for key,item in pairs(items) do
+				result:tag('item', item):reset()
+			end
+			stream:send(st.stanza('iq',{
+				to = stanza.attr.from,
+				from = stanza.attr.to,
+				id = stanza.attr.id,
+				type = 'result'
+			}):add_child(result))
+			return true
+		end
+	end);
+	
+	stream:hook("ready", function ()
+		stream:disco_local_services(function (services)
+			for _, service in ipairs(services) do
+				for identity in pairs(stream.disco.cache[service.jid].identities) do
+					local category, type = identity:match("^(.*)/(.*)$");
+					stream:event("disco/service-discovered/"..category, {
+						type = type, jid = service.jid;
+					});
+				end
+			end
+		end);
+	end, 5);
+end
+
+-- end of disco.lua